Prevalence, incidence, and risk factors of secondary malignancies in PV: A real-world study

Results from a real-world, retrospective cohort study evaluating the prevalence, incidence, and risk factors of secondary malignancies in adults with polycythemia vera (PV) were published in Blood Advances by Pemmaraju et al. Using Optum Market Clarity electronic health record (EHR) data and linked medical and pharmacy claims from 70 million patients in the US, 20,089 patients with established or newly diagnosed PV were analyzed to evaluate predictors of secondary malignancies and the association with cytoreductive therapies. 

Key data: Overall, 36% of patients had ≥1 new or ongoing non-PV malignancy, with a prevalence rate of 109.7 events per 1,000 patient-years (PY); 28% developed new non-PV malignancies over 4.3 years of follow-up, with an incidence rate of 76 events per 1,000 PY. The prevalence and incidence of new-onset melanoma or non-melanoma skin cancer (NMSC) was 9.1% and 7.4%, respectively. Key risk factors for any secondary malignancy included age ≥80 years (hazard ratio [HR], 2.159), pre-index cytoreductive treatment (HR, 1.883), age 60–79 years (HR, 1.781), elevated platelets (HR, 1.706), white blood cell (WBC) count ≥25 × 10³/μL (HR, 1.589), WBC count 15 to <25 × 10³/μL (HR, 1.237), and a history of cancer (HR, 1.231). Patients receiving ≥4 weeks of hydroxyurea had higher melanoma or NMSC incidence vs phlebotomy alone (31.6 vs 17.7/1,000 PY), though these findings may reflect differences in underlying disease burden.  

Key learning: Patients with PV, particularly older individuals and those exposed to hydroxyurea, are at increased risk of secondary malignancies, especially skin cancers, supporting consideration of routine dermatologic surveillance.